I. Field of the Invention
This invention relates generally to photoelectric transducing systems, and more specifically to the construction of a small, compact, rugged assembly which can be used as a module in a variety of products where a light source and light sensor are to be coupled to analog circuits or to analog/digital hybrid circuits.
II. Discussion of the Prior Art
In the digital data processing field as well as in electric control systems, it is often desirable to sense the passage of some indicia on a carrier past a fixed location. For example, in document reading apparatus, such as is used in sensing information from a conventional 80-column card, photo-optic devices can be used to detect the passage of a hole or a contrasting mark. Similarly, in process control applications, it is commonly desired to detect the passage of a product along a conveyor or the edge of an object passing between supply and take-up reels. In many applications, the transducing heads are subjected to a hostile environment, requiring rugged packaging to avoid failures due to shock, vibration or contamination.